One of the abnormalities in processing occurring in a computer is memory leak. The memory leak is the phenomenon that a memory area, which a program occupies for the purpose of processing, remains unreleased for some reason and the available memory area decreases. In order to investigate the cause of the occurrence of the memory leak, it is useful to sample the memory dump information in a state where the memory leak has occurred. However, in general, the level of difficulty in investigating the cause of the occurrence of the memory leak is said high.
In an example of the technique related to the memory dump, a memory space is divided into memory areas and the priority of each memory area is determined, and then the information stored in the memory area is compressed in the order of the determined priority and output into a dump file. In another example of the technique, when there are continuous same codes in data of a memory area, the data is compressed and sampled according to a predetermined rule.
Please see, for example, Japanese Laid-open Patent Publications No. 2009-205254 and No. 05-233383.
When an abnormality in processing, such as the memory leak, has occurred, the power supply of a computer is usually turned off and turned on to dissolve the abnormal state. Before the power supply of the computer is turned off, investigation information that is used for investigation of the cause of the occurrence of the abnormality is collected and recorded on a nonvolatile storage medium inside the computer.
Here, also in performing the collection processing of investigation information, a certain amount of memory area may be needed as a work area. However, when a work area for collection of investigation information is secured in advance inside a memory during normal operation, in which no abnormality has occurred, the available memory capacity decreases by the amount of this work area, which may affect the performance of the computer during normal operation.